Comparison Of The Clinical Effect Between Surrounded Atlanto-axial New Hook Rod Systems And Nail Rod Systems On Atlanto-axial Instability

Objective: Initially evaluate the clinical effects of new atlas surrounding hook rod internal fixation system to treat atlantoaxial instability by comparing the different indexes and data in perioperative period and follow-up data about new atlas surrounding hook rod internal fixation system(A group) and screw internal fixation system(B group) treating atlantoaxial instability.Methods:Select randomly some patients diagnosed with atlantoaxial instability from spine surgery department of Chenzhou No.1 People’s Hospital from June 2009 to December 2013, choose surgical cases according to the used criteria, collect case material and divide those cases into new atlas surrounding hook rod internal fixation system(A group) and screw internal fixation system(B group) with each group having 22 cases. Both groups adopt autogenous iliac bone graft or allogeneic bone graft. Observe JOA grades, operation time, the length ofoperative incision, intraoperative blood soss, the volume of drainage from postoperative incision, hospitalization time, and JOA and Frenkel grades, rate of fusion and Atlantoaxial joint stability(measure atlas-dens interval ADI) three months, six months and one year after operation.Results:No patients had their vertebral artery and spinal cord damaged because of operation error. all patients of the two groups were discharged from hospital without infection in lungs, urinary system and wound. 44 patients were fellow up for 6-12 months averaging 9±3 months. All grafted bones fused with their bones. There are comparable differences in operation time, intraoperatve blood soss, the volume of drainage from postoperative incision and hospitalization time; there is no comparable differences in JOA and Frenkel grades and Atlantoaxial joint stability.(P>0.05).Conclusion:Compared with atlantoaxial posterior screw fixation method, the operation method has the features of easy operation, rapid recovery and a similar biomechanical stability and rate of bone graft fusion to screw system; it adopts hook to fix arcus posterior atlantis which lowers the risks of iatrogenic vascular injuries and nerve injuries; therefore, the operation method is one operation method worth promoting among atlantoaxial posterior bone graft fusion internal fixation methods.